We haven't heard from Jenny or Eric since they were shipped off to London to "go to school" (we're so worried), Vanessa hasn't been seen since she stole Dan's (Penn Badgley) Great American Novel and scampered off to Barcelona, and we can only assume that Carter is currently gambling his life away in some shady underground bar. Sigh, come back to us, friends.Ideally, we'd love to see Jenny, Eric, Vanessa and Carter stop by Gossip Girl's before the show airs its last episode ever this winter. But if you had to choose one character for a surprise guest appearance, who would it be?!